1. Field of the Invention
The present invention relates to pulse code modulation digital filters and more particularly to a digital filter system which converts between different sampling rates while accomplishing digital filtering by interpolation.
2. Description of the Prior Art
Digital filtering of pulse code modulation systems has been accomplished in the past by circuitry directed to this purpose. Other circuits have been devised to convert between different rates of pulse code modulation. However, combined circuitry that can accomplish the digital filtering code rate conversion (both increasing and decreasing) and the processing of multiplex channels has not been previously devised.